Multiple-stage impact-turbine.



N0. s74,9s5. PATENTBD DEC. 31, 1907' 0. JUNGGREN v MULTIPLE STAGE IMPACT TURBINE.

APPLICATION FILED AUG. 9, 1906.

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" y I r PATENTED DEC. 31, 1907.

0. JUNGGREN. MULTIPLE STAGE IMPACT TURBINE.

APPLIOATION FILED AUG. 9, 1906.

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pa an QRAQ I r In vent/0r: Oscar" dunggren,

- pressure and NITED STATES PATENT OFFICE.

OSCAR JUNGGREN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION ,OF NEW YORK.

MULTIPLESTAGE manner-TURBINE.

Specification of Letters Patent.

Patented 'Dec. 31, "1907.

Application filed August 9. 1905- Serial No. 273,361-

type operating on'the jet or impact principle 1 are capable. of efficiently abstracting the energy from the motive fluid delivered thereto, but as now constructed they are subject to certain losses which it is the purpose of this invention to prevent or overcome.

As now constructed the motive fluid, which may be of any suitable character but for the purposes of this description will be referred to as steam, is. admitted to the turbine through suitably formed nozzles .of comparatively large cross-section of discharge, covering only a very limited arc of the first stage bucket Wheel or wheels. 4 The buckets themselves are relatively deep in order that the necessary amount of steam can impinge thereon and pass through the bucket spaces to developthe required power. This means that the majority of the buckets, at least in the early stages, are not only idle during a large portion-of each rotation of the wheel but are actually opposing a certain resistance to rotation due to their fan-like action. In ddition to this there is a certain resistance to rotation due to the friction between the body of the wheel and bubket supports and resistance or due .to the energy required to start the dead steam in the spaces between the idle buckets into motion as the latter pass in front of the nozzles. The buckets pass the nozzles under high velocity, 350 t0450 feet per second not being unusual. buckets are filled with dead steam at the they are located, and before the steam jet can perform any useful work it has to start this dead steam into motion and get. it out of the way. This obviously requires a certain amount ,of energy. The amount required for each bucket space is small, but the of which the following is a specifisults in l'osses of Another loss is occasioned by the currents 100 The spaces between the density of the stage in which aggregate is considerable Calculation shows that in a certain machine of 2000kilo-watts rated capacity the energy required to start the dead steam into motion may-consume as much as 2% per cent. of the total energy required under full-load conditions. These losses are greatest in the high-pressure sta e,

and decrease by stages as the'density of t e I steam decreases. These figures differ of course with different machines and are given merely as an illustration.

employed the losses are correspondingly increased because the dead steam in the bucket spaces in front of each nozzle has to be discharged before the buckets become fully effective. The. amount of moisture in the '65 When two or more separated nozzles or groups of nozzles are dead steam also has to be taken into account in this connection.

ere is also an additional loss as the bucketsleave the active stream or jet because the bucket spaces are filled with a body of'steam moving at a given velocity, which, as soon as the supply is shut off by reason of the bucket spaces moving beyond a nozzle, or as soon as these spaces are adjacent to a blank section of an intermediate, immediately loses its velocity wholly or in large part, and therefore is incapable of performing its proper share of the work. To state the matter in a diflerent way, the rapidly moving buckets drag the steam with them to a certain extent out from under the supply nozzle thereby permitting the steam to leave the wheel without doing its full share of the work. Besides failing to per-- form its share of the work, this steam may be a source of further loss by interfering with the roper functioning of some of the other nozz es or buckets 'in the stage. Anything which tends to divert the fluid stream from its prescribed path is objectionable as it reone character'or another;

of steam circulating within the stage or Wheel compartment. These currents of steam mafy flow in various directions in the stage, as or example, from one side to another and parallel orsubstantiallyparallel to the Wheelbody or Web, where the nozzles-are angu larly dis laced about the wheel. These currents o steam tend to disturb the flow through the nozzles and create objectionable eddies and losses.-

My invention therefore has for'its object 110 as are desirable or necessary to efiectively abstract the energy from'the motive fluid. In each of thesestages are as many wheel. buckets as are necessary arranged inone or more rows to abstract the'velocity .of the steam wholly or in large part. When two or necessary amount.

more rows of ,wheel buckets. per stage are employed to fractionallyabstract the energy of the steam in said stage, intermediate buckets are located between each 'two rows. Ordinarily the intermediate buckets will be stationary, but they may revolve in.a direction opposite to the wheel if desired. Instead of making the buckets in the earlier stages relatively deep and wide, as iii the previous constructions, I make them relatively shallow 'and narrow, since they areall in ac tion'when the machine is 'in .operation.- Owing'to the fact that all of the wheel buckets are-active, I may make the diameter of'the wheels in one or more of' the high-pressure stages of less diameter than'those in the lowpressurestage or stages' Thisconstruction obviates the use of especially small nozzles and buckets in the earlier stage or stages, which may be objectionable in some cases owing to the difficulty of manufacture and also on account of the leakages.

Steam is admitted to the turbine through a number of nozzle orificesflof small crosssectional area which'convert a portion of the steam pressure into velocity, the sum total of said areas being sufiicient" to supply the .These nozzles or nozzle sections may be expanding or non-ex anding in character in some or all of the difierent stages. The nozzle orifices or passages should be so closely associated and arranged that the steam issues therefrom in the form of a solid unbroken "column or belt which is. cylindrical in cross-section. These nozzles instead of acting on a limited arc 'of the wheel circumference in the different stages as in the former construction,- are so arranged that they act on the entire circumference of the wheel.

In addition to the admission nozzles, noz zles are provided for each stage which are similar in their arrangement and mode of.

operation. These nozzles have a somewhat greater cross sectlonal area, due to the increased volume of the steam caused by the reduced pressure, but in each stage the fluid discharged therefrom should act on all of the buckets. These nozzles may also be expand-- ing or non-appending in character, and the discharge ori ces or passages. should be so substantially cylindrical and hollow body,

the contour ofwhich is at no point broken. This arrangement of steam flow obviates the losses due to the fan-like action of the buckets, the losses caused by starting dead steam in the'bucket spaces into motion, the

dragging of the column of steam out of its proper plane or path by reason of the high rotative bucket speed, and finally 'it holds the, steam particles at the periphery of the wheelsand in line with the nozzles and buckets andgthus prevents any cross-currents. This also prevents the steam from striking the adja'centwalls of the casing or the diaphragins between stages and rebounding against the buckets and posing rotation.

The buckets in the stages should be so constructed and arranged with respect to the wheels or supports that'there are no projections whatsoever acting to retard, the rotation of the wheels. 'This is particularly important in the high-pressure stages where the density of the steam is high. As an example of what is meant, the parts of the Wheel should be perfectly smooth with no projecting bolt-heads, nuts, ribs, projections, etc. The Wheel parts should be made assmooth as possible, and preferably also the interior of the wheel casing and the supports for the intermediate buckets and nozzles. By making the buckets smaller in the first stage than is possible with partial injection machines of the'same power there is a material gain due to the fact that the buckets do not offer so much opposition to'rotation.

thus op- Located within one or more of the stages,

and preferably in all of them, is a ring presenting a smooth unbroken surface to the wheel and in close proximity thereto. This ring should be separated from the wheel by a clearance which is less than that between the wheel and intermediate buckets so as to prevent them from contacting and causing damagej This is an'important feature since the buckets are relatively small and constitute the more delicate part of the organization? The .ring may be'made in one piece or in segments, and it may form an integral part of a casing, wall or diaphragm or partition between stages, or it may be separable therefrom. It is preferable to provide one or more for each stage and to 'form it or them as integral parts of the diaphragm. This 5 adds greatly to the-simplicity of the 'construction, decreases the amount of machine work, labor in handling, and tendency of theparts to distort due'to heat changes.

With a turbine constructed as above I 'may and prefer to use a. throttling type of governing mechanism and throttle the admission of steam to the first stage, since it is desirable not to interrupt the continuity of the fluid column. The overload "condition can be taken care of by admitting live steam to'.the subsequent stages oflower pressureafter the first, through nozzles having the proper ratio of ex ansion. The throttle valve or valves may e operated by the shaft governor directly or through suitable relay -fluid-pressure nature.' I may also govern the turbine by admitting steam'i-n periods I and governing the length of the periods. I 25 may also govern the turbine by cutting the admission; nozzle sections into and out 'of service in resp'onse to load changes. The.

valves control ng the passage of fluid to the nozzles or nozzle sectionsmay be and pref erably' are separately actuated. The valves may be controlled electrically, hydraulic-. ally, mechanically or otherwise as desired -to best meet. the. requirements of service.

. In the accompanying drawings which illustrate one embodiment of my invention,

. Figure 1 is an axial section ofa vertical shaft, multi-stage turbine; Fig. 2 is a plan'view of the same showingcertainp'arts broken away.

for the pu 'os'e of illustration; Fig. 3 is a de-' tail View sowing the relation of the nozzles to. thewheel and intermediate buckets; Fig. 4 is a dia rammatic illustration of the unbroken" cy indrical column 'of motive fluid.

flowing through the turbine.

1 representsthe'. casing of the turbine which is supported by ajsuit'able base 2, the

. latter being-provided with a chamber thatis connected to a condenser or to atmospheric exhaust; The casing divided. bydiazfphragms 3 into stages 3% vide shaft 5 which is supported in suitablebearings. At the point where the shaft passes provi ed. 7 Each of the wheels in the earlier stages-is providedwithftwo rows of wheel buckets8 between which is an annular rowf,

offintermediate buckets 9 that serveto directthe passage of steam from one row of wheel buckets to the-next. Thewheel buck-- ets are provided with ring-like supports which are secured to the wheel byrivets .10 and which are flush so as not to offer resistance to rotation. ,In order to'take the cenduit 27.

each stageis pro-- with .a Wheel 4. The Wheels are mounted one above the other on the vertical through the head 6 a. suitable packing? trifugal strains off-of therivets a tongue and groove 111 is provided between each bucket support and, the wheel. The wheel is provided with a shoulder near the periphery,

the sidesurfaces ofwhich are flush with the sides of the bucket supports. The surfaces of thewheel are finishedso asto offer aminimum resistance to rotation. The' construction of the last two stages is somewhat-different, inasmuch as a-sin le row of wheel buckets is provided foreac stageins'tead of two. The wheels 12 and. 13 are mounted upona common support or hub 14 which is .mountedon the'main shaft 5, Located between the wheels is' a ring or half dia'phragm 15} The inner surface of the half-diaphragm isfini'shed, as is also the periphery of the support 14, and between thesetwofinished surleakage. The half diaphragfn is supported by an internal-shoulder 17 formed on the base 2 ofth'e machine and is provided with a peripheral flange 18 upon which rests the diapl1ragm'.19. -The other diaphragms are supported by internal shoulders 20 formed on the inner Walls of thewheelcasing, the latter being divided into suitable segments, the planes. of division being parallel with the shaft. 7,.The diaphragms 3 and the half-diaphragm 15 are provided with suitable strengthening ribs adjacent to the nozzles. The surfaces of the diaphra ms adjacent to' the wheels are. finished an are separated .facesis. a suitable packing 16 to prevent from the wheels by' a clearance, measured in an axial plane, :which is preferably-somewhat. less than the clearances between the wheel and intermediate buckets and between the Wheel buckets and the nozzles, so that any rubbing between the wheel. and the stationary parts will take place, not on the sharpened ed es of the buckets, but on the large flat :sur aces formed on parts of substantial size.

Mounted ontop of the head is a steam I chest. 25 which supplies steam or other elasticfluid to allfof the admission nozzles 26. Steam-is admitted to the chest by the 0011 The passa e of fluid there'through is controlled by the't 'rottle valve 28. This throttle valve under thecontrol of a speedresp-on'sive device 29 that is either mounted on the 'main shaft or driven therefrom 'by suitable gearin 30. As the speedof the turthrottle valve; 28 opens. orcloses by an amount sufiicient to satisfythe demand for steam. The; throttle valve and governor are shown m a more or. ]ess:d1agrammatic manner fo r the purpose of sii'nplicity illustration. 31 represents the supply pipe leading from the boiler and 32. a shut-ofl va'l've'whe'reby the turbine canbe stopped. The admission nozzle 26 is ofth expand bine changes. ue to variationsin load, the

ing's'ectionalized type, best shownin Fig. 3. It bolted .to'the underside of the head 6.v

This nozzle, as well as those in the subsequent stages, simultaneously supplies steam to all of the wheel buckets located adjacent thereto and the steam issues therefrom in. the form of an unbroken cylindrical column.

- The second stage nozzle 33 is of the same construction as nozzle 26, except that the passages are somewhat greater in cross-sectional area, owing to the increased-volume of the steam-to be handled, due to the decreased pressure. This nozzle is detachably secured to an overhanging shoulder 34 on the interior of thewhe el casing. The nozzle 35 for the third stage, 'is formed directly in the diaphragm. In the present instance, the nozzle is formed by castingthin, metal plates intothe diaphragm, these thin plates serving as partitions for directing and expanding the steam as it flows through them." The construction of the subsequent nozzles being the same," further description is unnecessary.

Owing to theenormous expansion of'the steam between the initial and final stages,

- the passa es'of the admission nozzles are made smal and'the first stage buckets arev made short in the radial dimension and relatively narrow in the direction of flow. The

remaining buckets throughout the turbine increase 111 radial depth, and also in width from the high to the low pressure stages.

' In Fig.4isshown diagrammatically the colunni of steam as it flows through the turbine.

This figure is not made to scale, but'is in-v r lindrical column throughout through the turbine.

' patentstatutes, I have described the princi tended merely as an illustration-of the fact that the steam preserves an unbroken cyits passage In accordance with the provisions of the ple of operation of my invention, together '"wlth the apparatus which I now consider to I represent the best embodiment thereof; but I desire to have it understood that the appa-- ratus shown is only illustrative, and that'the invention can be carried outby other means,

What I claim'as new, and desire to secure by Letters Patent of the United States, is,

1. In an elastic-fluid turbine, the combina tion'of a casing, diaphragms dividing the cas, ing into a plurality of stages, a'nozzle for each stage that converts acertain portion-of the pressure of the motive fluid into velocity and simultaneously discharges it in the form of an unbroken cylindrical column to all of thewheel buckets, Wheel buckets in the high pressure stage that are short and narrow, and

-Wheel buckets in the low-pressure sta eythat are relatively lon and wide, all of sai .buck ets abstracting W olly or in large part the velocity of the motive fluid due to the-preced ing nozzle and at the sametime preservingthe continuity of the fluid column; suhstan-g tially as set forth.

2. In an elastic-fluid turbine wherein pottions-of the pressure of the motive-fluid are successively converted into velocity and the velocity abstracted by stages, the combination of a sectionalized nozzle in each stage for discharging motive fluid in an unbroken cylindrical column against all of the buckets adjacent thereto to produce rotation and also to prevent bucket losses, and rows of Wheel and intermediate buckets for abstracting the energy of the motive fluid by stages. and for fractionally abstracting the energy of being less than that of the-wheel in the w-pressure stage.

3. In an elastic-fluid turbine wherein. por-- tions of the pressure of the motive fluid are successively converted into velocity and the I velocity abstracted by stages, the combination of a plurality of stages, rows of wheel and intermediate buckets for abstracting the energyof the motive fluid in said stages, sin

. the fluid ineach stage,. the diameter of the 'wheel in the high-pressure stage 0 gle rows of wheel buckets for the low pres-.

sure stages and one or more nozzlesfor each tive fluid into velocity and simultaneously discharge it against all of the buckets in an stage which convert the pressure of the mounbroken column to produce rotationand at the same time'reduce bucket losses, the said nozzles and buckets'being arranged'in' axial alinement so that the motive fluid enters the first wheelaiid leaves the last in the form of a hollow; cylinder.

4. In an elastic-fluid turbine wherein per- 'tions of thepressure of the motive fluid are successively converted into velocity and thevelocity abstracted by stages, the combination of a casing, diaphragms for dividing-it into stages, one. 1; more sectionalized nozzles stages'to' decrease rotation losses. r 5. In-an.elastic-fluidturbine wherein'por tions of the pressure of motive fluid are.- suc cessivel converted into velocity and the velocity a, stracted by stages, the-combination 'of one or more nozzles. for each of the .stages,,'

which convert the pressure of the fluid into high to the ow -pressure stage,1siipports for th'e'buckets-presentin smooth unbroken surfaces to'the fluid in t e stages, and surfaces l adjacent the wheel periphery, to prevent roe 'tation losses.-" 4

-velo( 3ity' and simultaneously discharge it against all of the .wheel buckets to produce rotation, ,andin an unbroken cylindrical column toprevent bu'cket losses,-whe e1 buckets in the stagesjrevolving in front of the nozzles all .of-which" are active at 'a'll times, the bucketsinclfeasin in widthand deptlrfrom the 6. In an'elestic-jflu id tfirbihe Wherein' por- 'angement of nozzles. and wheel bucketsbe "15 tiens 6f the ressure of the motive fluid ajre mg such that they ere acti-ve at all times and successiVlyconvrted into velocityand the .pres'e rve the ."contin'uitg of the fluid; column,

'- x elecityebs 't l'acted-by s'tages, the'combina the buckets in'zthe hig pressurestage being itlon of e-Jcasmgdiaphragms which divide .the" relatively short'and parrew,"and:those i-n-thei I casing into c'o'mpaxtments, 'a,.b11cket wheel." "subsequent stages increasing. in" width and for eacli compartment fcr'each stagefwhi'c'h Simultaneously d1"sdescnbed.

, sectionalized fiozzle length, substaptiallyeeand'fpl the piiypose char es'metiveflui'd in an unbroken cyli'n ,In -witfiess whel-eofi l halve iliereimto set .drica, cchimn against allof the Wheel buckhand-this- 7th .ets, ;a;1 1. ahnular'steamfchcst mounted on thev 1 da of Au use, 1905.

. OSCAR NGGREN. head f-thecasing and asepql ate annulanset .Wi'tn'esses: g j of intermediate buckets for each stage that is BE'1-{J AM1.'1-5* B. HIRE:

"situated I between the 3; diephrag'ims, the'er HELEN ORFORD. 

